Photo Credit: gorodenkoff
The following is a summary of “Accelerometer-derived movement features as predictive biomarkers for muscle atrophy in neurocritical care: a prospective cohort study,” published in the August 2024 issue of Critical Care by Schmidbauer et al.
The fundamental mechanisms underlying intensive care unit-acquired weakness (ICUAW) in neurocritical care involve physical inactivity and muscle atrophy. The lack of quantifiable biomarkers for inactivity made it challenging to evaluate its relative significance compared to other conditions under the syndromic diagnosis of ICUAW.
Researchers conducted a retrospective study to test the hypothesis using non-invasive, body-fixed accelerometers to measure active movement. Subsequently, they developed a machine learning model to predict muscle atrophy.
They conducted the cohort study within the MINCE registry (Metabolism and Nutrition in Neurointensive Care, DRKS-ID: DRKS00031472). Atrophy of the rectus femoris muscle (RFM) relative to baseline (day 0) was assessed on days 3, 7, and 10 following intensive care unit (ICU) admission. The measurement was the dependent variable in a generalized linear mixed model, which used Least Absolute Shrinkage and Selection Operator (LASSO) regularization and nested cross-validation.
The results showed that 407 patients were screened, from which 53 patients (mean age 59.2 years, SD 15.9; 31 [58.5%] male) with 91 available accelerometers were enrolled. By day 10, RFM thickness changed by −19.5% (SD 12.0). Among 12 demographic, clinical, nutritional, and accelerometer-derived variables, baseline RFM muscle mass (beta −5.1, 95% CI −7.9 to −3.8) and the proportion of active movement (% activity) (beta 1.6, 95% CI 0.1 to 4.9) were identified as significant predictors of muscle atrophy. Incorporating movement features into the prediction model substantially improved performance on an unseen test data set (including movement features: R2 = 79%; excluding movement features: R2 = 55%).
They concluded that active movement was a key risk factor for muscle atrophy in patients under neurocritical care, as measured with thigh-fixed accelerometers.
Source: ccforum.biomedcentral.com/articles/10.1186/s13054-024-05067-y
